A car takes 4 hours to reach a destination traveling at a speed of 63 km/h. How long will it take to cover the same distance if the car travels at the speed of 56 km/h? Do these quantities (time and speed) vary directly or inversely? Find the constant of variation.

Respuesta :

Answer:

It will take 4.5hrs to cover the same distance

The constant of variation,k=252

Step by step explanation

Given that,

[tex]speed = \frac{distance}{time} [/tex]

From the question

Time=4hr

Speed=63km

By substitution we obtain,

[tex]63= \frac{distance}{4} [/tex]

Cross multiplying we get,

[tex]distance=63 \times 4[/tex]

[tex]distance=252km[/tex]

Now,

speed=56km

Distance Covered=252km

By substitution:

We obtain,

[tex]56= \frac{252}{time} [/tex]

Cross multiply

[tex]56\times time=252 [/tex]

Divide through by 56

[tex]time= \frac{252}{56} [/tex]

[tex]time=4.5hrs[/tex]

From the formula,

[tex]speed= \frac{distance}{time} [/tex]

Which means that, speed and time varies inversely.

[tex]speed\propto \frac{1}{time} [/tex]

Let k be variation constant

This implies that

[tex]speed = k \times \frac{1}{time} [/tex]

[tex]k=speed \times{time} [/tex]

Taken,

Time=4hrs

speed=56km

[tex]k=56\times4[/tex]

[tex]k=252[/tex]